Space Weather

Professor Clare Watt

Department of Mathematics Physics and Electrical Engineering at Northumbria University

image

Professor of Space Physics

Space weather specialist

CLARE.WATT@NORTHUMBRIA.AC.UK

https://researchportal.northumbria.ac.uk/en/researchers/clare-watt(020912be-b929-477e-aaab-f981975e7b14).html

The space surrounding the Sun, planets and moons in our solar system is not quite a vacuum, but a sparse domain of high energy electrons, protons and other ions. The amount and energy of these particles is controlled not by gravity, but by electromagnetic fields which have their sources on the Sun or other magnetised bodies, such as Earth. Changes in our space environment are known as space weather, and in this lecture Professor Watt described its effects on our 21st Century technology and our efforts to forecast it.

The following are notes from the on-line lecture. Even though I could stop the video and go back over things there are likely to be mistakes because I haven’t heard things correctly or not understood them. I hope Professor Watt and my readers will forgive any mistakes and let me know what I got wrong.

Professor Watt began her talk my stating she has always been a space enthusiast. A number of years ago she was able to fulfil a dream by visiting the National Air and Space Museum, part of the Smithsonian Institution.

https://www.si.edu/

https://en.wikipedia.org/wiki/Smithsonian_Institution

The Smithsonian Institution also known simply as The Smithsonian, is a trust instrumentality of the United States composed as a group of museums and research centres. It was founded on August 10, 1846, “for the increase and diffusion of knowledge”.

https://en.wikipedia.org/wiki/National_Air_and_Space_Museum

The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C. It was established in 1946 as the National Air Museum and opened its main building on the National Mall near L’Enfant Plaza in 1976.

image

Above image shows Professor Watt with a space shuttle behind her.

Up until quite recently people thought that the space between planets, stars, moons and comets looked like.

image

However, space is not a true vacuum.

Energetic hot plasma from the Sun interacts with the planets and the effects depends on whether the plants have a magnetic field

image

Distances and sizes not to scale

What is between the Sun and the planets are very important.

The space actually contains electrons, protons, and alpha particles (helium nuclei)

https://en.wikipedia.org/wiki/Electron

The electron is a subatomic particle, symbol e−, whose electric charge is negative one elementary charge (-1.6 x 10-19C). Electrons are generally thought to be elementary particles because they have no known components or substructure. The electron has a mass that is approximately 1/1836 that of the proton (me = 9.11 x 10-31kg).

https://en.wikipedia.org/wiki/Proton

A proton is a subatomic particle, symbol p+, with a positive electric charge of +1e (+1.6 x 10-19C) elementary charge and a mass (1.67 x 10-27kg) slightly less than that of a neutron.

https://en.wikipedia.org/wiki/Alpha_particle

Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways.

The symbol for the alpha particle is α or α2+. Because they are identical to helium nuclei, they are also sometimes written as He2+ or 42He2+ indicating a helium ion with a +2 charge (missing its two electrons).

Neutral particles aren’t present as they tend to coagulate around rocks and other solid materials.

The charge particles are from coming from the Sun. It’s a bit like the Sun is “boiling” off like water molecules leaving water when it has reached its boiling point.

The number density of the particles is roughly 1 electron/proton pair per cm3. On Earth there about 109 particles (such as oxygen and nitrogen) per cm3.

Particles in space are very energetic and these make a difference to the atmospheres of planets.

Temperature is a method of measuring the average kinetic energy of particles. For gas particles the formula is E = (3/2)kT where k is the Boltzmann constant and T is the absolute temperature (in kelvin)

https://courses.lumenlearning.com/boundless-chemistry/chapter/kinetic-molecular-theory/

The energy of the solar wind is about 10eV (with an equivalent temperature of 110,000K). The energy/temperature actually rises within the magnetosphere to about 1keV (with an equivalent temperature of 11MK).

1eV = 1.6 x 10-19J

https://en.wikipedia.org/wiki/Solar_wind

The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between 0.5 and 10 keV. The composition of the solar wind plasma also includes a mixture of materials found in the solar plasma: trace amounts of heavy ions and atomic nuclei C, N, O, Ne, Mg, Si, S, and Fe. There are also rarer traces of some other nuclei and isotopes such as P, Ti, Cr, Ni, Fe 54 and 56, and Ni 58,60,62. Embedded within the solar-wind plasma is the interplanetary magnetic field. The solar wind varies in density, temperature and speed over time and over solar latitude and longitude. Its particles can escape the Sun’s gravity because of their high energy resulting from the high temperature of the corona, which in turn is a result of the coronal magnetic field.

At a distance of more than a few solar radii from the Sun, the solar wind reaches speeds of 250–750 km/s and is supersonic. The flow of the solar wind is no longer supersonic at the termination shock. Other related phenomena include the aurora (northern and southern lights), the plasma tails of comets that always point away from the Sun, and geomagnetic storms that can change the direction of magnetic field lines.

Space Weather Hazards

image

https://en.wikipedia.org/wiki/Space_weather

Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the time varying conditions within the Solar System, including the solar wind, emphasizing the space surrounding the Earth, including conditions in the magnetosphere, ionosphere, thermosphere, and exosphere. Space weather is distinct from but conceptually related to the terrestrial weather of the atmosphere of Earth (troposphere and stratosphere). The term space weather was first used in the 1950s and came into common usage in the 1990s.

The high energy particle environment around the planets is affected by solar activity causing space weather.

Space weather leads to hazards to the equipment in orbit around the Earth. Electrons land on surfaces and build up. When they reach a certain level (charging) they discharge, and this could be cyclical. If they build up enough, they can penetrate the metal that is found in the satellites that orbit the Earth. Its like putting a metal box in a high radiation environment of alpha and beta particles.

https://en.wikipedia.org/wiki/Beta_particle

A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay. There are two forms of beta decay, β− decay and β+ decay, which produce electrons and positrons respectively. Beta particles with an energy of 0.5 MeV have a range of about one metre in air; the distance is dependent on the particle energy.

Beta particles are a type of ionizing radiation and for radiation protection purposes are regarded as being more ionising than gamma rays, but less ionising than alpha particles. The higher the ionising effect the lower the penetrating power of the radiation.

Satellites are very vulnerable to the high energy electrons. Penetrating the metal, they can interfere with the electronics.

These high energy particles can also affect the electronics in aeroplanes. The upper atmosphere does provide some protection but there are big problems at the magnetic poles because the magnetic protection is weaker there.

If you carefully at the image below you can see there are obvious gaps at the north and south poles.

https://en.wikipedia.org/wiki/Earth%27s_magnetic_field

image

Artist’s concept of the Earth’s magnetosphere. The rounded, bullet-like shape represents the bow shock as the magnetosphere confronts solar winds. The area represented in grey, between the magnetosphere and the bow shock, is called the magnetosheath, while the magnetopause is the boundary between the magnetosphere and the magnetosheath. The Earth’s magnetosphere extends about 10 Earth radii toward the Sun and perhaps similar distances outward on the flanks. The magnetotail is thought to extend as far as 1,000 Earth radii away from the Sun. 1: Bow shock 2: Magnetosheath 3: Magnetopause 4: Magnetosphere 5: Northern tail lobe 6: Southern tail lobe 7: Plasmasphere

Earth’s magnetic field, also known as the geomagnetic field, is the magnetic field that extends from the Earth’s interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in the Earth’s outer core: these convection currents are caused by heat escaping from the core, a natural process called a geodynamo.

There are still dangers from space weather at ground level. Any changes to the electrical environment that the Earth sits in can induce electric currents in the top layers of the atmosphere (called the ionosphere) quite close to the poles.

https://en.wikipedia.org/wiki/Atmosphere_of_Earth

The atmosphere of Earth is the layer of gases, commonly known as air, retained by Earth’s gravity, surrounding the planet Earth and forming its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth’s surface, absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation).

image image

Earth’s atmosphere Lower 4 layers of the atmosphere in 3 dimensions as seen diagonally from above the exobase. Layers drawn to scale, objects within the layers are not to scale. Aurorae shown here at the bottom of the thermosphere can actually form at any altitude in this atmospheric layer.

The ionosphere is a region of the atmosphere that is ionized by solar radiation. It is responsible for auroras. During daytime hours, it stretches from 50 to 1,000 km and includes the mesosphere, thermosphere, and parts of the exosphere. However, ionization in the mesosphere largely ceases during the night, so auroras are normally seen only in the thermosphere and lower exosphere. The ionosphere forms the inner edge of the magnetosphere. It has practical importance because it influences, for example, radio propagation on Earth.

https://slideplayer.com/slide/8260485/

The problem is that if you induce a current in one part you can induce currents elsewhere and if you have long wires carrying electricity, say from a power station to a town (the national grid), the current induced in them from the ionosphere will cause problems.

https://en.wikipedia.org/wiki/Geomagnetically_induced_current

Geomagnetically induced currents (GIC), affecting the normal operation of long electrical conductor systems, are a manifestation at ground level of space weather. During space weather events, electric currents in the magnetosphere and ionosphere experience large variations, which manifest also in the Earth’s magnetic field. These variations induce currents (GIC) in conductors operated on the surface of Earth. Electric transmission grids and buried pipelines are common examples of such conductor systems. GIC can cause problems, such as increased corrosion of pipeline steel and damaged high-voltage power transformers. GIC are one possible consequence of geomagnetic storms, which may also affect geophysical exploration surveys and oil and gas drilling operations.

There have been cases of power grid transformers being melted by a space weather event and causing the entire grid to be knocked out.

https://en.wikipedia.org/wiki/Transformer

A transformer is a passive electrical device that transfers electrical energy from one electrical circuit to another, or multiple circuits. A varying current in any one coil of the transformer produces a varying magnetic flux in the transformer’s core, which induces a varying electromotive force across any other coils wound around the same core. Electrical energy can be transferred between separate coils without a metallic (conductive) connection between the two circuits. Faraday’s law of induction, discovered in 1831, describes the induced voltage effect in any coil due to a changing magnetic flux encircled by the coil.

Transformers are most commonly used for increasing low AC voltages at high current (a step-up transformer) or decreasing high AC voltages at low current (a step-down transformer) in electric power applications, and for coupling the stages of signal-processing circuits. Transformers can also be used for isolation, where the voltage in equals the voltage out, with separate coils not electrically bonded to one another.

Since the invention of the first constant-potential transformer in 1885, transformers have become essential for the transmission, distribution, and utilisation of alternating current electric power. A wide range of transformer designs is encountered in electronic and electric power applications. Transformers range in size from RF transformers less than a cubic centimetre in volume, to units weighing hundreds of tons used to interconnect the power grid.

image

Idealised single-phase tranformer also showing the path of magnetic flux through the core. Magnetic flux is produced by the primary winding, and contained by the high permeability core, links the secondary winding. The mutual inductance between the two windings results in an induced voltage on the secondary side, whose magnitude is determined by the ratio of turns between the two windings. Reference: Daniels, A (1976). Introduction to Electrical Machines. Macmillan Publishers. ISBN 0-333-19627-9.

https://en.wikipedia.org/wiki/Electrical_grid

An electrical grid, electric grid or power grid, is an interconnected network for delivering electricity from producers to consumers. It consists of:

generating stations that produce electric power

electrical substations for stepping electrical voltage up for transmission, or down for distribution

high voltage transmission lines that carry power from distant sources to demand-centres

distribution lines that connect individual customers

https://www.thesciencethinkers.com/how-does-the-power-grid-work/

image

A famous example of space weather knocking out a grid occurred on the 13th March 1989. A severe geomagnetic storm caused the collapse of the Hydro-Québec power grid in a matter of seconds as equipment protective relays tripped in a cascading sequence of events. Six million people were left without power for nine hours, with significant economic loss. Since 1989, power companies in North America, the United Kingdom, Northern Europe, and elsewhere have invested in evaluating the GIC risk and in developing mitigation strategies.

https://en.wikipedia.org/wiki/Halloween_solar_storms,_2003

The Halloween solar storms were a series of solar flares and coronal mass ejections that occurred from mid-October to early November 2003, peaking around October 28–29. This series of storms generated the largest solar flare ever recorded by the GOES system. Satellite-based systems and communications were affected, aircraft were advised to avoid high altitudes near the polar regions, and a one-hour-long power outage occurred in Sweden as a result of the solar activity. Aurorae were observed at latitudes as far south as Texas and the Mediterranean countries of Europe

https://en.wikipedia.org/wiki/Geostationary_Operational_Environmental_Satellite (GOES)

The Geostationary Operational Environmental Satellite (GOES), operated by the United States’ National Oceanic and Atmospheric Administration (NOAA)’s National Environmental Satellite, Data, and Information Service division, supports weather forecasting, severe storm tracking, and meteorology research.

image

The above image shows some of the effects of the solar storm. Nobody suffered health wise but it was very expensive to sort out all the problems it caused.

Scientists are waiting for the “Big One”

https://en.wikipedia.org/wiki/Carrington_Event

The Carrington Event was a powerful geomagnetic storm on September 1–2, 1859, during solar cycle 10 (1855–1867). A solar coronal mass ejection (CME) hit Earth’s magnetosphere and induced the largest geomagnetic storm on record. The associated “white light flare” in the solar photosphere was observed and recorded by British astronomers Richard Carrington and Richard Hodgson. The storm caused strong auroral displays and wrought havoc with telegraph systems. The now-standard unique IAU identifier for this flare is SOL1859-09-01.

https://en.wikipedia.org/wiki/Coronal_mass_ejection

A coronal mass ejection (CME) is a significant release of plasma and accompanying magnetic field from the solar corona. They often follow solar flares and are normally present during a solar prominence eruption. The plasma is released into the solar wind, and can be observed in coronagraph imagery.

The Carrington Event took down parts of the recently created US telegraph network, starting fires and shocking some telegraph operators. Some telegraphers, on the other hand, were able to continue operating with their batteries disconnected, powered by the aurora-induced currents in the lines, with normal or improved signal quality. Very strange electrical effects.

image

A very active region on the Sun. Sunspots of September 1, 1859, as sketched by Richard Carrington. A and B mark the initial positions of an intensely bright event, which moved over the course of five minutes to C and D before disappearing.

https://en.wikipedia.org/wiki/Richard_Christopher_Carrington

Richard Christopher Carrington (26 May 1826 – 27 November 1875) was an English amateur astronomer whose 1859 astronomical observations demonstrated the existence of solar flares as well as suggesting their electrical influence upon the Earth and its aurorae; and whose 1863 records of sunspot observations revealed the differential rotation of the Sun.

https://en.wikipedia.org/wiki/Richard_Hodgson_(publisher)

Richard Hodgson (1804, in Wimpole Street, Marylebone, Central London – 4 May 1872, in Chingford, Essex) was an English publisher and amateur astronomer.

The image below left shows a chart from a magnetic observatory. The chart was simply a piece of paper on a revolving drum and a pen made the trace on it. The pen would be attached to whatever was measuring the magnetic force (see a sort of version below right).

image

The magnetic observations went off the chart.

The reason for the fact that part of the trace was missing was because the pen fell off due to the perturbations being so large.

A solar storm of this magnitude occurring today would cause widespread electrical disruptions, blackouts and damage due to extended outages of the electrical grid. The solar storm of 2012 was of similar magnitude, but it passed Earth’s orbit without striking the planet, missing by nine days.

https://en.wikipedia.org/wiki/Solar_storm_of_2012

image

The coronal mass ejection, as photographed by STEREO.

The solar storm of 2012 was an unusually large and strong coronal mass ejection (CME) event that occurred on July 23 that year. It missed the Earth with a margin of approximately nine days, as the equator of the Sun rotates around its own axis with a period of about 25 days. The region that produced the outburst was thus not pointed directly towards the Earth at that time. The strength of the eruption was comparable to the 1859 Carrington event that caused damage to electrical equipment worldwide, which at that time consisted mostly of telegraph systems.

Threat to spacecraft

Charge builds up on the surface, which then discharges

https://spaceweather.rra.go.kr/effect/english/07_03_01

Surface charging to a high voltage does not usually cause immediate problems for a spacecraft. However, electrical discharges resulting from differential charging can damage surface material and create electromagnetic interference that can result in damage to electronic devices. Variations in low energy plasma parameters around the spacecraft, along with the photoelectric effect from sunlight, cause most surface charging. Due to the low energy of the plasma, this type of charging does not penetrate directly into interior components. Surface charging can be largely mitigated through proper materials selection and grounding techniques. Surface charging occurs predominantly during geomagnetic storms. It is usually more severe in the spacecraft local times of midnight to dawn but can occur at any time. Night to day, and day to night transitions are especially problematic during storms since the photoelectric effect is abruptly present or absent, which can trip discharges. Additionally, thruster firings can change the local plasma environment and trigger discharges.

Deep dielectric charging

https://en.wikipedia.org/wiki/Dielectric

A dielectric (or dielectric material) is an electrical insulator that can be polarised by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the material as they do in an electrical conductor but only slightly shift from their average equilibrium positions causing dielectric polarisation. Because of dielectric polarisation, positive charges are displaced in the direction of the field and negative charges shift in the direction opposite to the field (for example, if the field is moving in the positive x-axis, the negative charges will shift in the negative x-axis). This creates an internal electric field that reduces the overall field within the dielectric itself. If a dielectric is composed of weakly bonded molecules, those molecules not only become polarised, but also reorient so that their symmetry axes align to the field.

https://spaceweather.rra.go.kr/effect/english/07_03_02

Deep dielectric charging is a problem primarily for high altitude spacecraft. At times, when Earth is immersed in a high-speed solar wind stream, the Van Allen belts become populated with high fluxes of relativistic (>~1 MeV) electrons. These electrons easily penetrate spacecraft shielding and can build up charge where they come to rest in dielectrics such as coax cable, circuit boards, electrically floating radiation shields, etc. If the electron flux is high for extended periods, abrupt discharges (tiny “lightening strokes”) deep in the spacecraft can occur. High fluxes of these electrons vary with the 11-year solar cycle and are most prevalent late in the cycle and at solar minimum. Occasionally, high-energy electron events recur with a 27-day periodicity – the rotation period of the Sun. Discharges appear to correlate well with long periods of high fluxes. At these times, charge build-up exceeds the natural charge leakage rate of the dielectric. The charge builds and discharge occurs after the breakdown voltage is reached. In the past, some energetic electron enhancements at GEO (geosynchronous orbit) have approached two weeks in duration. It was at the end of one of these long duration enhancements in 1994 that two Canadian satellites experienced debilitating upsets.

The internal discharge produces heat and large voltages.

In all cases the discharge of electrons causes a lot of damage so they are nick-names “killer” electrons

image

NOAA/NASA GOES R-series

https://www.goes-r.gov/mission/mission.html

The Geostationary Operational Environmental Satellite-R Series (GOES-R) is the next generation of geostationary weather satellites

http://apps.agi.com/satelliteviewer/

https://maps.esri.com/rc/sat2/index.html

image

19,287 satellites loaded

image

Slide focusing on geosynchronous satellites around the Earth

https://www.gsa.europa.eu/european-gnss/galileo/galileo-european-global-satellite-based-navigation-system

image

https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)

Galileo is a global navigation satellite system (GNSS) that went live in 2016, created by the European Union through the European Space Agency (ESA), operated by the European GNSS Agency (GSA),[6] headquartered in Prague, Czech Republic, with two ground operations centres in Fucino, Italy, and Oberpfaffenhofen, Germany. The €10 billion project is named after the Italian astronomer Galileo Galilei. One of the aims of Galileo is to provide an independent high-precision positioning system so European nations do not have to rely on the US GPS, or the Russian GLONASS systems, which could be disabled or degraded by their operators at any time. The use of basic (lower-precision) Galileo services is free and open to everyone. The higher-precision capabilities are available for paying commercial users. Galileo is intended to provide horizontal and vertical position measurements within 1-metre precision, and better positioning services at higher latitudes than other positioning systems. Galileo is also to provide a new global search and rescue (SAR) function.

Navigation satellites are in positions where there are a lot of high energy electrons present.

Questions and Answers part 1

1) Do satellites need more protection when they pass through the Van Allen belt?

https://en.wikipedia.org/wiki/Van_Allen_radiation_belt

A Van Allen radiation belt is a zone of energetic charged particles, most of which originate from the solar wind, that are captured by and held around a planet by that planet’s magnetic field. Earth has two such belts and sometimes others may be temporarily created.

Earth’s two main belts extend from an altitude of about 640 to 58,000 km above the surface, in which region radiation levels vary. Most of the particles that form the belts are thought to come from solar wind and other particles by cosmic rays. By trapping the solar wind, the magnetic field deflects those energetic particles and protects the atmosphere from destruction.

The belts are in the inner region of Earth’s magnetosphere. The belts trap energetic electrons and protons. Other nuclei, such as alpha particles, are less prevalent. The belts endanger satellites, which must have their sensitive components protected with adequate shielding if they spend significant time near that zone. In 2013, NASA reported that the Van Allen Probes had discovered a transient, third radiation belt, which was observed for four weeks until it was destroyed by a powerful, interplanetary shock wave from the Sun.

https://upload.wikimedia.org/wikipedia/commons/transcoded/2/21/Van_Allen_Belts.ogv/Van_Allen_Belts.ogv.480p.vp9.webm

This CGI video illustrates changes in the shape and intensity of a cross section of the Van Allen belts.

image

A cross section of Van Allen radiation belts

Yes, the satellites do need protection as they pass through the Van Allen belts

2) Has anyone’s health been affected by space weather events.

Not that Professor knows of. If people’s health was affected it wasn’t due to the space weather. If it there was going to be health problems then you would expect it in people who live near the poles as there is less magnetic protection there.

Hospital data has shown no evidence. If people have been affected it would be indirect. Technology going haywire for instant.

Back to the talk

image

In the 1950’s scientists had a very simplified view of the Solar System. They believed that above the Earth’s atmosphere there wasn’t much there. Anything that was lost from the atmosphere, was lost for good.

The image above shows the men responsible for the first US satellite.

https://en.wikipedia.org/wiki/Bill_Pickering_(rocket_scientist)

William Hayward Pickering ONZ KBE (24 December 1910 – 15 March 2004) was a New Zealand-born rocket scientist who headed Pasadena, California’s Jet Propulsion Laboratory (JPL) for 22 years, retiring in 1976.

https://en.wikipedia.org/wiki/James_Van_Allen

James Alfred Van Allen (September 7, 1914 – August 9, 2006) was an American space scientist at the University of Iowa. He was instrumental in establishing the field of magnetospheric research in space.

https://en.wikipedia.org/wiki/Wernher_von_Braun

Wernher Magnus Maximilian Freiherr von Braun (March 23, 1912 – June 16, 1977) was a German-born American aerospace engineer and space architect. He was the leading figure in the development of rocket technology in Nazi Germany and a pioneer of rocket and space technology in the United States.

https://en.wikipedia.org/wiki/Explorer_1

Explorer 1 was the first satellite launched by the United States and was part of the U.S. participation in the International Geophysical Year. The mission followed the first two satellites the previous year; the Soviet Union’s Sputnik 1 and 2, beginning the Cold War Space Race between the two nations.

Explorer 1 was launched on January 31, 1958 at 22:48 Eastern Time (February 1, 03:48 UTC) atop the first Juno booster from LC-26 at the Cape Canaveral Missile Annex in Florida. It was the first spacecraft to detect the Van Allen radiation belt, returning data until its batteries were exhausted after nearly four months. It remained in orbit until 1970 and was followed by more than ninety scientific spacecraft in the Explorer series.

Explorer 1 was given Satellite Catalogue Number 4 and the Harvard designation 1958 Alpha 1, the forerunner to the modern International Designator.

The satellite had a Geiger counter on board to measure the radiation effects in the atmosphere as a function of height from the surface of the Earth.

image

Initially there was a decline, as expected, but then, all of a sudden there was a large rapid increase. The machine had reached saturation point at just over 120 counts. It was inundated. The signal dropped down as the satellite’s altitude dropped. The Geiger counter couldn’t cope at the highest point.

A member of the team was heard to say “My God, space is radioactive”. Nobody expected this to be the case.

Physics that matters for space weather

Electrons, protons and alpha particles are so low in mass that gravity is not important. So, it isn’t gravity keeping them near the Earth and it isn’t gravity dealing with them near the Sun.

Electrons, proton and alpha particles are charged so they are affected by magnetic and electric fields. These keep the particles in place so they are really important,

The grand tour

image

The image above shows the current fleet of satellites investigating space weather, e.g. Van Allen Probes, NASA Parker Solar Probe and the Solar Orbiter.

https://en.wikipedia.org/wiki/Van_Allen_Probes

https://en.wikipedia.org/wiki/Parker_Solar_Probe

https://en.wikipedia.org/wiki/Solar_Orbiter

The Sun

The solar weather is ultimately due to the activity of the Sun

https://en.wikipedia.org/wiki/Sun

image

The Sun is the star at the centre of our Solar System. It is a nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy mainly as light and infrared radiation. It is by far the most important source of energy for life on Earth. Its diameter is about 1.39 million kilometres, or 109 times that of Earth, and its mass is about 330,000 times that of Earth. It accounts for about 99.86% of the total mass of the Solar System. Roughly three quarters of the Sun’s mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.[21]

The Sun is a G-type main-sequence star (G2V) based on its spectral class. As such, it is informally and not completely accurately referred to as a yellow dwarf (its light is closer to white than yellow). It formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most of this matter gathered in the centre, whereas the rest flattened into an orbiting disk that became the Solar System. The central mass became so hot and dense that it eventually initiated nuclear fusion in its core. It is thought that almost all stars form by this process.

In its core the Sun currently fuses about 600 million tons of hydrogen into helium every second, converting 4 million tons of matter into energy every second as a result. This energy, which can take between 10,000 and 170,000 years to escape the core, is the source of the Sun’s light and heat. When hydrogen fusion in its core has diminished to the point at which the Sun is no longer in hydrostatic equilibrium, its core will undergo a marked increase in density and temperature while its outer layers expand, eventually transforming the Sun into a red giant. It is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury and Venus, and render Earth uninhabitable – but not for about five billion years. After this, it will shed its outer layers and become a dense type of cooling star known as a white dwarf, and no longer produce energy by fusion, but still glow and give off heat from its previous fusion.

The Solar activity has an 11-year cycle from solar minimum to solar maximum

https://en.wikipedia.org/wiki/Solar_cycle

The solar cycle or solar magnetic activity cycle is a nearly periodic 11-year change in the Sun’s activity measured in terms of variations in the number of observed sunspots on the solar surface. Sunspots have been observed since the early 17th century and the sunspot time series is the longest continuously observed (recorded) time series of any natural phenomena.

Levels of solar radiation and ejection of solar material, the number and size of sunspots, solar flares, and coronal loops all exhibit a synchronized fluctuation, from active to quiet to active again, with a period of 11 years.

This cycle has been observed for centuries by changes in the Sun’s appearance and by terrestrial phenomena such as auroras. Solar activity, driven both by the sunspot cycle and transient aperiodic processes govern the environment of the Solar System planets by creating space weather and impact space- and ground-based technologies as well as the Earth’s atmosphere and also possibly climate fluctuations on scales of centuries and longer.

Understanding and predicting the sunspot cycle remains one of the grand challenges in astrophysics with major ramifications for space science and the understanding of magnetohydrodynamic phenomena elsewhere in the Universe.

image

The images above come courtesy of the SoHo observatory

https://en.wikipedia.org/wiki/Solar_and_Heliospheric_Observatory

The Solar and Heliospheric Observatory (SOHO) is a spacecraft built by a European industrial consortium led by Matra Marconi Space (now Airbus Defence and Space) that was launched on a Lockheed Martin Atlas II AS launch vehicle on December 2, 1995, to study the Sun. It has also discovered over 3,000 comets. It began normal operations in May 1996. It is a joint project between the European Space Agency (ESA) and NASA. Originally planned as a two-year mission, SOHO continues to operate after over 25 years in space; the mission has been extended until the end of 2020 with a likely extension until 2022.

In addition to its scientific mission, it is a main source of near-real-time solar data for space weather prediction. Along with Wind, ACE, and DSCOVR, SOHO is one of four spacecraft in the vicinity of the Earth–Sun L1 point, a point of gravitational balance located approximately 0.99 astronomical units (AU) from the Sun and 0.01 AU from the Earth. In addition to its scientific contributions, SOHO is distinguished by being the first three-axis-stabilized spacecraft to use its reaction wheels as a kind of virtual gyroscope; the technique was adopted after an on-board emergency in 1998 that nearly resulted in the loss of the spacecraft.

image

The above image shows the Sun in different wavelengths of the electromagnetic spectrum.

https://directory.eoportal.org/web/eoportal/satellite-missions/s/soho

image

From left to right, the images shown in this view were taken at increasing wavelengths of UV light (171 Å, 195 Å, 284 Å and 304 Å, respectively)

The flares are the bright flashes and the coronal mass ejections are huge bubbles of plasma

The magnetic field/activity of the Sun changes. This is important for space weather.

image

image

SOHO is at Lagrange point 1 (L1)

At this point the satellite has an uninterrupted view of the Sun all the time

https://en.wikipedia.org/wiki/Lagrange_point

In celestial mechanics, the Lagrange points are orbital points near two large co-orbiting bodies. At the Lagrange points the gravitational forces of the two large bodies cancel out in such a way that a small object placed in orbit there is in equilibrium relative to the centre of mass of the large bodies.

There are five such points, labelled L1 to L5, all in the orbital plane of the two large bodies, for each given combination of two orbital bodies. For instance, there are five Lagrangian points L1 to L5 for the Sun–Earth system, and in a similar way there are five different Lagrangian points for the Earth–Moon system. L1, L2, and L3 are on the line through the centres of the two large bodies, while L4 and L5 each act as the third vertex of an equilateral triangle formed with the centres of the two large bodies. L4 and L5 are stable, which implies that objects can orbit around them in a rotating coordinate system tied to the two large bodies.

image

Lagrange points in the Sun–Earth system (not to scale) – a small object at any one of the five points will hold its relative position.

New mission – Parker Solar Probe

https://en.wikipedia.org/wiki/Parker_Solar_Probe

The Parker Solar Probe (abbreviated PSP; previously Solar Probe, Solar Probe Plus or Solar Probe+) is a NASA Space Probe launched in 2018 with the mission of making observations of the outer corona of the Sun. It will approach to within 9.86 solar radii (6.9 million km) from the centre of the Sun, and by 2025 will travel, at closest approach, as fast as 690,000 km/h, or 0.064% the speed of light.

image

On 29 October 2018, at about 18:04 UTC, the spacecraft became the closest ever artificial object to the Sun (it was able to do this because it had an amazing heat shield). The previous record, 42.73 million kilometres from the Sun’s surface, was set by the Helios 2 spacecraft in April 1976. As of its perihelion on 27 September 2020, the Parker Solar Probe’s closest approach is 13.5 million kilometres (it literally skimmed the top of the Sun) . This will be surpassed after each successive flyby of Venus.

The goals of the mission are:

Trace the flow of energy that heats the corona and accelerates the solar wind.

Determine the structure and dynamics of the magnetic fields at the sources of solar wind.

Determine what mechanisms accelerate and transport energetic particles.

New mission – Solar Orbiter

https://en.wikipedia.org/wiki/Solar_Orbiter

The Solar Orbiter (SolO) is a Sun-observing satellite, developed by the European Space Agency (ESA). SolO is intended to perform detailed measurements of the inner heliosphere and nascent solar wind, and perform close observations of the polar regions of the Sun, which is difficult to do from Earth, both serving to answer the question “How does the Sun create and control the heliosphere?”

SolO makes observations of the Sun from an eccentric orbit moving as close as ≈60 solar radii (RS), or 0.284 astronomical units (au), placing it inside Mercury’s perihelion of 0.3075 au. During the mission the orbital inclination will be raised to about 24°. The total mission cost is US$1.5 billion, counting both ESA and NASA contributions.

SolO was launched on 10 February 2020. The mission is planned to last 7 years.

image

https://sci.esa.int/web/solar-orbiter

image

https://astronomy.com/magazine/news/2020/08/what-will-solar-orbiters-mission-accomplish

https://directory.eoportal.org/web/eoportal/satellite-missions/s/solar-orbiter-mission

(Image below) Solar Orbiter trajectory to orbit the Sun (image credit: ESA). This satellite also has an amazing heat shield. It is going to be orbiting over the Sun’s poles looking for similarities and differences.

image

Question and Answers Part 2

1) What caused the Chicago blackout in 2020?

Professor Watt didn’t know, but I looked it up. It was cause by a storm.

2) What are the chances of another Carrington event?

There was an event in the early 50s?

When a big event happens, it is good to be able to measure it. An analogy would be the monitoring during floods. They can be measured and if they happen every so often. It allows preparations to be made.

The problem with space weather is that it has only recently been recognised as existing.

We are using space more and more with a reliance on electronic and electrical systems so we need to be prepared.

The 1950s event wasn’t measured very well because it wasn’t expected.

A Carrington even is expected every 100 to 150 years. It isn’t definite, but based on accumulated probabilities.

3) Future mission may go to Lagrange 4 or 5 because they will give different views of the Sun.

Back to the talk

The Solar atmosphere and the Solar wind are due to gases boiling into space.

https://en.wikipedia.org/wiki/Solar_wind

image

Ulysses’ observations of solar wind speed as a function of helio latitude during solar minimum. Slow wind (≈400 km/s) is confined to the equatorial regions, while fast wind (≈750 km/s) is seen over the poles. Red/blue colours show inward/outward polarities of the heliospheric magnetic field.

It sampled the Solar wind over the poles as well as the ecliptic plane and measured the solar wind speed, seen on the x-axis of the image above. Along the ecliptic plane the lines on the above image are very jagged which means most of the time the Solar wind is slow but sometimes it gets very fast. Speed is a big deal for the Solar wind.

The average speed of the solar wind is about 400km/s. At the polar orbits the speed is about 750 to 800km/s.

Between 1994 and 1995 Ulysses explored both the southern and northern polar regions of the Sun, respectively.

https://en.wikipedia.org/wiki/Ulysses_(spacecraft)

Ulysses is a decommissioned robotic space probe whose primary mission was to orbit the Sun and study it at all latitudes. It was launched in 1990 and made three “fast latitude scans” of the Sun in 1994/1995, 2000/2001, and 2007/2008. In addition, the probe studied several comets. Ulysses was a joint venture of NASA and the European Space Agency (ESA) with participation from Canada’s National Research Council. The last day for mission operations on Ulysses was June 30, 2009.

To study the Sun at all latitudes, the probe needed to change its orbital inclination and leave the plane of the Solar System. To change the orbital inclination of a spacecraft to about 80° requires a large change in heliocentric velocity, the energy to achieve which far exceeded the capabilities of any launch vehicle. To reach the desired orbit around the Sun, the mission’s planners chose a gravity assist manoeuvre around Jupiter, but this Jupiter encounter meant that Ulysses could not be powered by solar cells. The probe was powered instead by a radioisotope thermoelectric generator (RTG).

The spacecraft was originally named Odysseus, because of its lengthy and indirect trajectory to study the solar poles. Ulysses was originally scheduled for launch in May 1986 aboard the Space Shuttle Challenger on STS-61-F. Due to the loss of Challenger, the launch of Ulysses was delayed until October 6, 1990 aboard Discovery (mission STS-41).

https://en.wikipedia.org/wiki/Ecliptic

The ecliptic is the plane of Earth’s orbit around the Sun. From the perspective of an observer on Earth, the Sun’s movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the background of stars. The ecliptic is an important reference plane and is the basis of the ecliptic coordinate system.

The image below shows the plane of Earth’s orbit projected in all directions forms the reference plane known as the ecliptic. Here, it is shown projected outward (grey) to the celestial sphere, along with Earth’s equator and polar axis (green). The plane of the ecliptic intersects the celestial sphere along a great circle (black), the same circle on which the Sun seems to move as Earth orbits it. The intersections of the ecliptic and the equator on the celestial sphere are the vernal and autumnal equinoxes (red), where the Sun seems to cross the celestial equator.

image

image

The image above is a computer simulation of the Solar wind as if you were looking down on one of the poles. The yellow bits are the fast stream of Solar wind, shooting out like laser beams.

Solar wind is very variable and makes a big difference to space weather.

Stereo

https://en.wikipedia.org/wiki/STEREO

STEREO (Solar Terrestrial Relations Observatory) is a solar observation mission. Two nearly identical spacecraft were launched in 2006 into orbits around the Sun that cause them to respectively pull farther ahead of and fall gradually behind the Earth. This enables stereoscopic imaging of the Sun and solar phenomena, such as coronal mass ejections.

Contact with STEREO-B was lost in 2014, but STEREO-A is still operational.

image

Two space craft, one ahead of the Earth’s orbit and one behind. This gives two different views of the Sun increasing the likelihood of getting images of coronal mass ejections. The above left image is showing a coronal mass ejection thankfully not directed at Earth

image

Animation of STEREO’s trajectory

https://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Animation_of_STEREO_trajectory_relative_to_Sun_and_Earth.gif/220px-Animation_of_STEREO_trajectory_relative_to_Sun_and_Earth.gif

The principal benefit of the mission was stereoscopic images of the Sun. In other words, because the satellites are at different points along the Earth’s orbit, but distant from the Earth, they can photograph parts of the Sun that are not visible from the Earth. This permitted NASA scientists to directly monitor the far side of the Sun, instead of inferring the activity on the far side from data that can be gleaned from Earth’s view of the Sun. The STEREO satellites principally monitored the far side for coronal mass ejections — massive bursts of solar wind, solar plasma, and magnetic fields that are sometimes ejected into space.

Since the radiation from coronal mass ejections, or CMEs, can disrupt Earth’s communications, airlines, power grids, and satellites, more accurate forecasting of CMEs has the potential to provide greater warning to operators of these services. Before STEREO, the detection of the sunspots that are associated with CMEs on the far side of the Sun was only possible using helioseismology, which only provides low-resolution maps of the activity on the far side of the Sun. Since the Sun rotates every 25 days, detail on the far side was invisible to Earth for days at a time before STEREO. The period that the Sun’s far side was previously invisible was a principal reason for the STEREO mission.

Solar activity and the Earth

Solar activity has around an 11-year cycle

The magnetic fields are carried out throughout the Solar System by the Solar wind. These magnetic fields interact with the Earth’s magnetic fields.

image

The magnetic field around the Earth shield’s it from the Solar wind. It is so important that we visualise them. But this process isn’t perfect as magnetic field lines don’t actually exist.

https://cnx.org/contents/SXdeOFrb@1/Magnetic-Field-Lines

image

Magnetic field lines are defined to have the direction in which a small compass needle points when placed at a location in the field. The strength of the field is proportional to the closeness (or density) of the lines. If the interior of the magnet could be probed, the field lines would be found to form continuous, closed loops. To fit in a reasonable space, some of these drawings may not show the closing of the loops; however, if enough space were provided, the loops would be closed.

The representation of magnetic fields by magnetic field lines is very useful in visualising the strength and direction of the magnetic field. As shown above, each of these lines forms a closed loop, even if not shown by the constraints of the space available for the figure. The field lines emerge from the north pole (N), loop around to the south pole (S), and continue through the bar magnet back to the north pole.

Magnetic field lines have several hard-and-fast rules:

The direction of the magnetic field is tangent to the field line at any point in space. A small compass will point in the direction of the field line.

The strength of the field is proportional to the closeness of the lines. It is exactly proportional to the number of lines per unit area perpendicular to the lines (called the areal density).

Magnetic field lines can never cross, meaning that the field is unique at any point in space.

Magnetic field lines are continuous, forming closed loops without a beginning or end. They are directed from the north pole to the south pole.

The last property is related to the fact that the north and south poles cannot be separated.

Magnetic field lines are a construct which allows us to imagine what the magnetic field looks like. They are so useful that we draw them in.

The magnetosphere

https://en.wikipedia.org/wiki/Magnetosphere

https://upload.wikimedia.org/wikipedia/commons/transcoded/c/c7/Rattling_Earth%27s_Force_Field.ogv/Rattling_Earth%27s_Force_Field.ogv.480p.vp9.webm

A rendering of the magnetic field lines of the magnetosphere of the Earth.

In astronomy and planetary science, a magnetosphere is a region of space surrounding an astronomical object in which charged particles are affected by that object’s magnetic field. It is created by a star or planet with an active interior dynamo.

In the space environment close to a planetary body, the magnetic field resembles a magnetic dipole. Farther out, field lines can be significantly distorted by the flow of electrically conducting plasma, as emitted from the Sun (i.e. the solar wind) or a nearby star. Planets having active magnetospheres, like the Earth, are capable of mitigating or blocking the effects of solar radiation or cosmic radiation, that also protects all living organisms from potentially detrimental and dangerous consequences. This is studied under the specialized scientific subjects of plasma physics, space physics and aeronomy.

image

The image above is an artist’s impression of how the solar wind interacts with the Earth’s magnetic field.

The Solar wind is coming in from the left and there appears to be a tear in the shield. This can happen when the Sun’s magnetic field, which is directed in the opposite direction to the Earth’s, interacts with the Earth’s magnetic field. The phenomenon is called reconnection.

https://en.wikipedia.org/wiki/Magnetic_reconnection

Magnetic reconnection is a physical process occurring in highly conducting plasmas in which the magnetic topology is rearranged and magnetic energy is converted to kinetic energy, thermal energy, and particle acceleration.

The qualitative description of the reconnection process is such that magnetic field lines from different magnetic domains (defined by the field line connectivity) are spliced to one another, changing their patterns of connectivity with respect to the sources.

Magnetic reconnection in Earth’s magnetosphere is one of the mechanisms responsible for the aurora.

The tearing of the Earth’s magnetic field allows the solar wind to creep into the Earth’s shielding bubble.

The Earth’s radiation belts

image

Deep within the heart of the Earth’s magnetic field are the tiny regions (coloured pink in the above image) that trap radiation. The particles inside them are more energetic (highest energy electrons are here) than the rest of the space surrounding the Earth. They are called the Van Allen radiation belts because he was part of the team that discovered them.

The speed of the energetic particles are fractions of the speed of light. Some of them can reach speeds up to 0.8c (c = 3 x 108m/s)

The particles trapped by the Earth’s magnetic field gain access to the Earth’s magnetosphere through the tearing of the shield mentioned above. They are trapped there because the Earth’s magnetic field is curved

https://www.nasa.gov/mission_pages/rbsp/mission/fun-facts.html

Science exploration of the radiation belts in 1990

image

https://en.wikipedia.org/wiki/CRRES

The Combined Release and Radiation Effects Satellite (CRRES) was launched on July 25, 1990, into a geosynchronous transfer orbit (GTO) for a nominal three-year mission to investigate fields, plasmas, and energetic particles inside the Earth’s magnetosphere. As part of the CRRES program, the SPACERAD (Space Radiation Effects) project, managed by Air Force Geophysics Laboratory, investigated the radiation environment of the inner and outer radiation belts and measured radiation effects on state-of-the-art microelectronics devices.

image

Contact with the CRRES spacecraft was lost on October 12, 1991, and was presumed to be due to onboard battery failure.

Van Allen Probes

image

https://en.wikipedia.org/wiki/Van_Allen_Probes

The Van Allen Probes (VAP), formerly known as the Radiation Belt Storm Probes (RBSP), were two robotic spacecraft that were used to study the Van Allen radiation belts that surround Earth. NASA conducted the Van Allen Probes mission as part of the “Living With a Star” program. Understanding the radiation belt environment and its variability has practical applications in the areas of spacecraft operations, spacecraft system design, mission planning and astronaut safety. The probes were launched on 30 August 2012 and operated for seven years. Both spacecraft were deactivated in 2019 when they ran out of fuel. They are expected to deorbit during the 2030s.

The mission’s general scientific objectives were to:

Discover which processes – singly or in combination – accelerate and transport the particles in the radiation belt, and under what conditions.

Understand and quantify the loss of electrons from the radiation belts.

Determine the balance between the processes that cause electron acceleration and those that cause losses.

Understand how the radiation belts change in the context of geomagnetic storms.

image

The Relativistic Electron Proton Telescope (REPT) turned on just two days after launch, mapping electron fluxes as the Van Allen Probes sped through the radiation belts. Each line in the diagram shows one orbit, and the colour bar on the right shows the intensity of electron flux. Scientists watched the outer electron belt spread and fade dramatically over the course of one month. Observing, and then predicting how the radiation belts react in response to solar activity is one of the goals of the Van Allen Probes’ mission.

JHU / APL, NASA

https://www.americanscientist.org/article/new-twists-in-earths-radiation-belts

https://skyandtelescope.org/astronomy-news/van-allen-probes-peek-at-radiation-belts/

Because it was vital that the two craft make identical measurements to observe changes in the radiation belts through both space and time, each probe carried the following instruments:

Energetic Particle, Composition, and Thermal Plasma (ECT) Instrument Suite; The Principal Investigator is Harlan Spence from University of New Hampshire. Key partners in this investigation are LANL, Southwest Research Institute, Aerospace Corporation and LASP

Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS); The Principal Investigator is Craig Kletzing from the University of Iowa.

Electric Field and Waves Instrument (EFW); The Principal Investigator is John Wygant from the University of Minnesota. Key partners in this investigation include the University of California at Berkeley and the University of Colorado at Boulder.

Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE); The Principal Investigator is Louis J. Lanzerotti from the New Jersey Institute of Technology. Key partners include the Applied Physics Laboratory and Fundamental Technologies, LLC.

Relativistic Proton Spectrometer (RPS) from the National Reconnaissance Office

What Professor Watt does

She builds improved numerical models of the high energy particles in the radiation belts

She can provide space weather forecasts in the same way as meteorologists do for normal weather

image

https://en.wikipedia.org/wiki/Low_Earth_orbit

A low Earth orbit (LEO) is an Earth-centred orbit with an altitude of 2,000 km or less (approximately one-third of the radius of Earth), or with at least 11.25 periods per day (an orbital period of 128 minutes or less) and an eccentricity less than 0.25. Most of the manmade objects in outer space are in LEO.

https://en.wikipedia.org/wiki/Medium_Earth_orbit

Medium Earth orbit (MEO), sometimes called intermediate circular orbit (ICO), is the region of space around Earth above low Earth orbit (altitude of 2,000 km above sea level) and below geosynchronous orbit (altitude of 35,786 km (22,236 mi) above sea level).

https://en.wikipedia.org/wiki/Geostationary_orbit

A geostationary orbit, also referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit 35,786 kilometres above Earth’s equator and following the direction of Earth’s rotation.

Creating numerical models

One of the reasons why Professor Watt wanted to do this lecture was to show her audience (predominantly A level students – age 16 to 19) how her mathematical models actually use physics that appears on A level and Scottish Highers syllabi. So, the work they are doing now will be useful later.

So how do charged particles move in magnetic fields?

A charged particle in a magnetic field will cause the charge particle move in a circle

https://courses.lumenlearning.com/boundless-physics/chapter/motion-of-a-charged-particle-in-a-magnetic-field/

Magnetic force is always perpendicular to velocity, so that it does no work on the charged particle. The particle’s kinetic energy and speed thus remain constant. The direction of motion is affected, but not the speed. This is typical of uniform circular motion. The simplest case occurs when a charged particle moves perpendicular to a uniform B-field, such as shown below. (If this takes place in a vacuum, the magnetic field is the dominant factor determining the motion.) Here, the magnetic force supplies the centripetal force.

The formula for centripetal force is F = mv2/r where m is the mass of the charged particle, v is its velocity and r is the radius of curvature.

The formula for the magnetic force on the charge particle is F = Bqv where B is the magnetic field strength, q is the charge on the particle and v is its velocity

image

A negatively charged particle moves in the plane of the page in a region where the magnetic field is perpendicular into the page (represented by the small circles with x’s—like the tails of arrows). The magnetic force is perpendicular to the velocity, and so velocity changes in direction but not magnitude. Uniform circular motion results.

If the two forces are equal you get the circular path and mv2/r = Bqv simplifying to mv/r = Bq and the radius of curvature = r = mv/Bq.

Of course, the Solar wind isn’t just one charged particle so a lot of charged particles and magnetic fields have to be analysed.

Also, the charge particle will have a velocity and if this is parallel to the direction of the magnetic field then it will follow a spiral/helix path (below left).

image

If the magnetic isn’t uniform (variations in its value or spatial structure) you end up with a bouncing motion (above right). Particles are spiralling and bouncing around.

If we consider how these particles move in the Earth’s magnetic field then you get the situation shown below

image

The paths of the particles are just the natural consequence of how charged particles move in magnetic fields and what happens as they bounce from one hemisphere to another. They are just drifting around the Earth.

F = qvBsinθ = ma

(ma = mass x acceleration and is a form of Newton’s second law)

The sinθ arises because the magnetic field may not be acting at 90o to the magnetic force.

The velocity = v = dx/dt = the rate of change of displacement

The acceleration a = F/m = dv/dt = rate of change of velocity

The equations shown are effectively the equations used to solve and produce big simulations.

“Just” keep solving the equations for about 108 representative electrons, and you can eventually make a forecast.

Of course, Professor Watt can’t do this on her own. She has a big team consisting of PhD student and postdocs.

The team does a lot of simulations and data analysis. Their ultimate aim is to be able to create space weather predictions for the MET office.

image

https://www.metoffice.gov.uk/

https://en.wikipedia.org/wiki/Met_Office

The Meteorological Office, abbreviated as the Met Office is the United Kingdom’s national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy led by CEO Penelope Endersby, who took on the role as Chief Executive in December 2018. The Met Office makes meteorological predictions across all timescales from weather forecasts to climate change.

https://www.metoffice.gov.uk/weather/specialist-forecasts/space-weather

https://www.metoffice.gov.uk/weather/learn-about/space-weather/met-office-role

image

The Met Office Space Weather Operations Centre (MOSWOC), based in Exeter, is one of three space weather prediction centres around the globe. It employs 6 to 10 people. The other centres are in South Africa and Australia.

https://blog.metoffice.gov.uk/tag/space-weather/

The Met office provides forecasts for businesses and the government for both the weather and space.

All the weather centres embed space weather into their services.

Professor Watts journey into space physics

image

https://en.wikipedia.org/wiki/Higher_(Scottish)

In the Scottish secondary education system, the Higher is one of the national school-leaving certificate exams and university entrance qualifications of the Scottish Qualifications Certificate (SQC) offered by the Scottish Qualifications Authority. It superseded the old Higher Grade on the Scottish Certificate of Education (SCE). Both are normally referred to simply as “Highers”.

The modern Higher is Level 6 on the Scottish Credit and Qualifications Framework.

The most able candidates in S5 typically take five Higher subjects, and matriculation requirements for courses are specified from a range from CC to AAAAA depending on the course and university.

https://en.wikipedia.org/wiki/GCE_Advanced_Level

The A Level (Advanced Level) is a subject-based qualification conferred as part of the General Certificate of Education, as well as a school leaving qualification offered by the educational bodies in the United Kingdom and the educational authorities of British Crown dependencies to students completing secondary or pre-university education.

A Levels are generally worked towards over two years. Normally, students take three or four A Level courses in their first year of sixth form, and most taking four cut back to three in their second year. This is because university offers are normally based on three A Level grades, and taking a fourth can have an impact on grades. Unlike other level-3 qualifications, such as the International Baccalaureate, A Levels have no specific subject requirements, so students have the opportunity to combine any subjects they wish to take. However, students normally pick their courses based on the degree they wish to pursue at university: most degrees require specific A Levels for entry.

Professor Watt’s research in Canada

image

She was able to visit the rocket range, that sent rockets up to study auroras.

image

https://en.wikipedia.org/wiki/Aurora

An aurora (plural: auroras or aurorae), sometimes referred to as polar lights (aurora polaris), northern lights (aurora borealis), or southern lights (aurora australis), is a natural light display in the Earth’s sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic).

Auroras are the result of disturbances in the magnetosphere caused by solar wind. These disturbances are sometimes strong enough to alter the trajectories of charged particles in both solar wind and magnetospheric plasma. These particles, mainly electrons and protons, precipitate into the upper atmosphere (thermosphere/exosphere).

The resulting ionization and excitation of atmospheric constituents emit light of varying colour and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on the amount of acceleration imparted to the precipitating particles. Precipitating protons generally produce optical emissions as incident hydrogen atoms after gaining electrons from the atmosphere. Proton auroras are usually observed at lower latitudes.

image

The above image shows part of the equipment sent up with a hi-altitude balloon.

https://en.wikipedia.org/wiki/High-altitude_balloon

High-altitude balloons are manned or unmanned balloons, usually filled with helium or hydrogen, that are released into the stratosphere, generally attaining between 18 and 37 km above sea level. In 2002, a balloon named BU60-1 reached a record altitude of 53.0 km.

Professor Watt today

“Things I never thought I’d get the chance to influence!”

These days Professor Wattis involved in many discussion panels as well as her research work. She is involved in decisions on what sort of instruments are used and what sort of experiments are carried out on the ISS.

image

https://en.wikipedia.org/wiki/International_Space_Station

The International Space Station (ISS) is a modular space station (habitable artificial satellite) in low Earth orbit. It is a multinational collaborative project between five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA (Japan), ESA (Europe), and CSA (Canada). The ownership and use of the space station is established by intergovernmental treaties and agreements. The station serves as a microgravity and space environment research laboratory in which scientific research is conducted in astrobiology, astronomy, meteorology, physics, and other fields. The ISS is suited for testing the spacecraft systems and equipment required for possible future long-duration missions to the Moon and Mars.

image

Professor Watt is also involved with the new lunar space station – The lunar gateway.

https://en.wikipedia.org/wiki/Lunar_Gateway

The Lunar Gateway, or simply the Gateway, is a planned mini-space station in lunar orbit intended to serve as a solar-powered communication hub, science laboratory, short-term habitation module, and holding area for rovers and other robots. It is expected to play a major role in NASA’s Artemis program, after 2024. While the project is led by NASA, the Gateway is meant to be developed, serviced, and utilized in collaboration with commercial and international partners: Canada (CSA), Europe (ESA), and Japan (JAXA). It will serve as the staging point for both robotic and crewed exploration of the lunar south pole, and is the proposed staging point for NASA’s Deep Space Transport concept for transport to Mars. Formerly known as the Deep Space Gateway (DSG), the station was renamed Lunar Orbital Platform-Gateway (LOP-G) in NASA’s 2018 proposal for the 2019 United States federal budget. When the budgeting process was complete, US$332 million had been committed by Congress to preliminary studies.

The science disciplines to be studied on the Gateway are expected to include planetary science, astrophysics, Earth observation, heliophysics, fundamental space biology, and human health and performance. Gateway development includes the International Space Station partners: NASA, ESA, JAXA, and CSA. Construction is planned to take place in the 2020s. The International Space Exploration Coordination Group (ISECG), which is composed of more than 14 space agencies including all major ones, has concluded that Gateway will be critical in expanding a human presence to the Moon, Mars, and deeper into the Solar System.

image

A career in space is a very good idea. The space inductrial sector is growing about 4% every year.

Questions and answers part 3

1) Will space weather affect geomagnetism?

Yes, a little. Earth magnetism has sources from within and they are changing over very large timescales, about 10000 years. The Earth’s magnetic field is weak

The origin of a very large magnetic field at the centre of our Solar System is the Sun.

The weaker magnetic force from the Earth interacts with the stronger magnetic force from the Sun. But the Earth’s magnetic field is a really good shield from the Solar wind. However, this might not have been the case in the past (or the future).

If you look at some of the other planets in the Solar System, like Mars, they don’t have a strong shielding magnetic field and this is one of the reasons why the atmosphere is so thin. The Solar winds stripped some of it away.

2) As we are entering a new Solar cycle are there going to be any large effects on Solar weather events?

Yes, definitely. During the time of Solar maximum, you expect more Solar magnetic effects. However, Solar cycles can vary. At the moment it is believed we are in an overall minimum Solar cycle and that over the last 50 years (which includes the space race) we haven’t experienced strong Solar cycles.

If you look back further than 50 years, looking at the sunspot record, there have been much stronger cycles.

Some of the best physicists in the world are trying to figure out what the next cycles will be like. Unfortunately, the different predictions don’t match very well.

The start of a cycle isn’t much help in trying to work out what the rest of the cycle will be like.

3) Is the Solar wind slower when it is closer to the Sun.

The answer is, its complicated. It is quite slow very close to the Sun, its subsonic.

The Solar wind accelerates through the Solar corona (which is way hotter than it should be). Parker solar and ESA missions are trying to answer questions about the velocities such as what accelerates the Solar wind and why does it reach speeds over 700km/s? If the Solar wind was just the Solar atmosphere boiling away then you wouldn’t expect such high speeds.

There is a small space above the photosphere where the Solar wind is being accelerated and as it passes through the Solar System its speed stays relatively constant as it isn’t really interacting with much. It does get less dense because it is spreading out, but it isn’t really slowing down.

4) Which particle of the Solar wind is the most damaging to the Earth’s atmosphere and technology in space?

Protons might as they are the most massive so you would probably prefer an electron to hit you. However, there are more high energy electrons in space than protons (high energy protons are quite rare), In the grand scheme of things high energy electrons are the most damaging as there are more of them.

5) Do you think space weather will become even more important in the future?

Yes, although she admitted that she did have a vested interest.

Yes, because we are relying on space more and more. The internet in space is going to be a very big thing soon.

https://en.wikipedia.org/wiki/Interplanetary_Internet

https://www.space.com/spacex-starlink-satellites.html

Communication is relying on satellites more and more and the plan is to move off Earth. Colonies on the Moon are planned and there is the potential of sending people to Mars. There is also the potential of mining asteroids.

A lot of future problems look like having space-based solutions

6) What will happen to space weather as the Sun evolves over time?

We don’t know how the Sun’s magneticity will change as it ages. However, this factor is the key as its size isn’t important.

Professor Watt did admit she is not an expert on this.

7) Would space weather pose a large risk to programs such as SpaceX’s Starlink or Artemis?

It could do, if their electronics are affected by a space weather event.

Questions not answered by Professor Watt.

8) Could space weather break the Internet?

https://www.google.com/search?q=Could+space+weather+break+the+Internet%3F&rlz=1C1CHBF_en-GBGB912GB912&oq=Could+space+weather+break+the+Internet%3F&aqs=chrome..69i57.901j0j7&sourceid=chrome&ie=UTF-8

9) Is there any way to harness space weather?

10) Are mechanical machines affected?

https://www.google.com/search?q=Are+mechanical+machines+affected+by+solar+weather&rlz=1C1CHBF_en-GBGB912GB912&oq=Are+mechanical+machines+affected+by+solar+weather&aqs=chrome..69i57.6653j0j7&sourceid=chrome&ie=UTF-8

11) is there a specific metal or heat absorber that is used for building satellites?

https://www.google.com/search?q=is+there+a+specific+metal+or+heat+absorber+that+is+used+for+building+satellites%3F&rlz=1C1CHBF_en-GBGB912GB912&oq=is+there+a+specific+metal+or+heat+absorber+that+is+used+for+building+satellites%3F&aqs=chrome..69i57j69i64.3903j0j9&sourceid=chrome&ie=UTF-8

12) Given that the sun has recently entered a new cycle, do scientists expect this to have a large effect on solar weather events?

https://www.google.com/search?q=Given+that+the+sun+has+recently+entered+a+new+cycle%2C+do+scientists+expect+this+to+have+a+large+effect+on+solar+weather+events%3F&rlz=1C1CHBF_en-GBGB912GB912&oq=Given+that+the+sun+has+recently+entered+a+new+cycle%2C+do+scientists+expect+this+to+have+a+large+effect+on+solar+weather+events%3F&aqs=chrome..69i57.1618j0j7&sourceid=chrome&ie=UTF-8

13) Can the Earth’s magnetic field be damaged from the forces acted upon it?

https://www.google.com/search?q=Can+the+Earth%E2%80%99s+magnetic+field+be+damaged+from+the+forces+acted+upon+it%3F&rlz=1C1CHBF_en-GBGB912GB912&oq=Can+the+Earth%E2%80%99s+magnetic+field+be+damaged+from+the+forces+acted+upon+it%3F&aqs=chrome.0.69i59.1277j0j7&sourceid=chrome&ie=UTF-8

14) You’re a space fan, what contributions did the Apollo program make to the field of space weather? I know the ALSEP pack had a sheet of foil to collect solar wind particles.

https://www.google.com/search?rlz=1C1CHBF_en-GBGB912GB912&biw=1280&bih=1079&sxsrf=ALeKk01eOq2kvO1JAGmILjdsfH54xc9qew%3A1604955735344&ei=V66pX6O0FPCf1fAPua-4iAE&q=what+contributions+did+the+Apollo+program+make+to+the+field+of+%22space+weather%3F%22&oq=what+contributions+did+the+Apollo+program+make+to+the+field+of+%22space+weather%3F%22&gs_lcp=CgZwc3ktYWIQAzIECCMQJzoECAAQR1C5XliRemDNqwFoAHACeACAAU2IAeUCkgEBNZgBAKABAaoBB2d3cy13aXrIAQjAAQE&sclient=psy-ab&ved=0ahUKEwjju_CDrvbsAhXwTxUIHbkXDhEQ4dUDCA0&uact=5

https://en.wikipedia.org/wiki/Apollo_Lunar_Surface_Experiments_Package

15) Do you think space weather will become even more important in the future?

https://www.google.com/search?q=Do+you+think+space+weather+will+become+even+more+important+in+the+future%3F&rlz=1C1CHBF_en-GBGB912GB912&oq=Do+you+think+space+weather+will+become+even+more+important+in+the+future%3F&aqs=chrome..69i57.4032j0j4&sourceid=chrome&ie=UTF-8

16) What would happen if we ever try to go to Mars?

https://www.google.com/search?q=What+would+happen+if+we+ever+try+to+go+to+Mars%3F&rlz=1C1CHBF_en-GBGB912GB912&oq=What+would+happen+if+we+ever+try+to+go+to+Mars%3F&aqs=chrome..69i57.3910j0j9&sourceid=chrome&ie=UTF-8

17) Would Global Warming be affected by space weather?

https://www.google.com/search?q=Would+Global+Warming+be+affected+by+space+weather%3F&rlz=1C1CHBF_en-GBGB912GB912&oq=Would+Global+Warming+be+affected+by+space+weather%3F&aqs=chrome..69i57j33i160.1867j0j7&sourceid=chrome&ie=UTF-8

18) Do you think the Kessler Syndrome will grow to stop all space advancements?

https://www.google.com/search?q=Do+you+think+the+Kessler+Syndrome+will+grow+to+stop+all+space+advancements%3F&rlz=1C1CHBF_en-GBGB912GB912&oq=Do+you+think+the+Kessler+Syndrome+will+grow+to+stop+all+space+advancements%3F&aqs=chrome..69i57.3535j0j9&sourceid=chrome&ie=UTF-8

19) What will happen to the space weather as the Sun progresses in its star cycle?

https://www.google.com/search?q=What+will+happen+to+the+space+weather+as+the+Sun+progresses+in+its+star+cycle%3F&rlz=1C1CHBF_en-GBGB912GB912&oq=What+will+happen+to+the+space+weather+as+the+Sun+progresses+in+its+star+cycle%3F&aqs=chrome..69i57.3063j0j9&sourceid=chrome&ie=UTF-8

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s